We are proposing to further analyze the molecular mechanisms involved in the act of histone phosphorylation and its correlation with DNA synthesis. We have designed experiments to tell us whether all the Fl and the F2A2 histones are phosphorylated each cell cycle, whether or not this is a single non-recurring event for any given molecule, and whether both newly synthesized or pre-existing histones are phosphorylated. We plan to inhibit DNA and/or protein synthesis in order to assay for dependence upon macromolecular synthesis of continuing phosphorylation and the extent of organizational coupling. We will attempt to answer the question of whether newly phosphorylated histone and newly synthesized DNA are spatially close to one another. We plan to study the inhibitory effect of cyclic AMP on tumor cell growth in terms of its effect upon histone phosphorylation. Finally, we will try to isolate a specific histone kinase, to purify it and to describe its properties and its enzymatic control.